Interior mirrors...

[McDesign]

I've been using this set-up for a couple years now, and it works fine. I drilled a 7/8" hole in the little coin tray left of the steering wheel, and used a threaded and an unthreaded 1/2" PVC (gray electrical, not plumbing) sweep.

Used box nuts above and below the tray bottom. I couldn't get it as tight as I liked, so I built up fillets above and below with J&B Weld.

Sprayed it all black. Mirror is made to clamp onto a 1" stalk, so perfect.

I actually sawed off the side view mirror protrusions from the removeable triangles at the front of the windows, and fiberglassed them flat before normal bodywork and paint.

The rearview is a nice glass curved unit from EBay; cames from Israel, IIRC - writing on it is in German.

[BamZipPow]

Modded one of the mirrors fer better adjustment on shallow windshields. Not sure how well it will stay in place over the long run.

[BamZipPow]

Installed the modified mirror in the wife's Cadillac El Dorado. The shallow windshield angle prevented the unmodified blind spot mirror from adjusting fer the shallow angle. No problem now!

The blind spot mirror is now on the same plane as the stock OEM exterior mirror so there shouldn't be that much of an adjustment from wide to narrow.

[BamZipPow]

I have discovered that if the blind spot mirror is mounted slightly higher than the OEM mirror...any glare you normally git in the OEM mirrors are usually minimized in the blind spot mirror because of the different viewing angle.

[BamZipPow]

Looks like Pep Boys sells the same mirror fer about $4 more.
http://www.pepboys.com/product/details/224659/01036

[slowmover]

Mirrors for a vehicle with trailer need a convergence point at/before 200'.

Ck state law.

Also, any device mounted on windshield interior is pretty much a no go if intrudes 6" from frame AND within wiper sweep of glass as seem from drivers position. (One or the other will apply).